From 6010d1f3edaa684faef5732be2ad0bb55093d48b Mon Sep 17 00:00:00 2001
From: Kenneth Reitz <me@kennethreitz.org>
Date: Tue, 26 Sep 2017 09:34:58 -0400
Subject: [PATCH] warn when using an older version of python

Signed-off-by: Kenneth Reitz <me@kennethreitz.org>
---
 bin/compile      |  5 ++++-
 bin/steps/python | 13 +++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/bin/compile b/bin/compile
index c288521..4b7682d 100755
--- a/bin/compile
+++ b/bin/compile
@@ -35,10 +35,13 @@ export BUILD_DIR CACHE_DIR ENV_DIR
 
 # Python defaults
 DEFAULT_PYTHON_VERSION="python-3.6.2"
+LATEST_3="python-3.6.2"
+LATEST_2="python-2.7.14"
+
 DEFAULT_PYTHON_STACK="cedar-14"
 PIP_UPDATE="9.0.1"
 
-export DEFAULT_PYTHON_VERSION DEFAULT_PYTHON_STACK PIP_UPDATE
+export DEFAULT_PYTHON_VERSION DEFAULT_PYTHON_STACK PIP_UPDATE LATEST_2 LATEST_3
 
 # Common Problem Warnings
 WARNINGS_LOG=$(mktemp)
diff --git a/bin/steps/python b/bin/steps/python
index 908d1b2..c2fd625 100755
--- a/bin/steps/python
+++ b/bin/steps/python
@@ -4,6 +4,19 @@ set +e
 runtime-fixer runtime.txt
 PYTHON_VERSION=$(cat runtime.txt)
 
+if [[ $PYTHON_VERSION == "python-2*" ]]; then
+  if [[ "$PYTHON_VERSION" != "$LATEST_2" ]]; then
+    puts-warn "The latest version of Python 2 is $LATEST_2. We recommend upgrading by specifying this version in a runtime.txt file."
+    puts "    Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+  fi
+else
+  if [[ "$PYTHON_VERSION" != "$LATEST_3" ]]; then
+    puts-warn "The latest version of Python 3 is $LATEST_2. We recommend upgrading by specifying this version in a runtime.txt file."
+    puts "    Learn More: https://devcenter.heroku.com/articles/python-runtimes"
+  fi
+
+fi
+
 if [[ "$STACK" != "$CACHED_PYTHON_STACK" ]]; then
     puts-step "Stack has changed from $CACHED_PYTHON_STACK to $STACK, clearing cache"
     rm -fr .heroku/python-stack .heroku/python-version .heroku/python .heroku/vendor